DLT-based End-to-end Inter-domain Transport Network Slice with SLA Management Using Cloud-based SDN Controllers (Demo Session) Lluis Gifre Renom * , Ricard Vilalta * , Sebastien Andreina † , Min Xie ‡ , Jane Frances Pajo ‡ , Konstantin Munichev † , H˚ akon Lønsethagen ‡ , Stanislav Lange § , Thomas Zinner § ,Giorgia Marson † , Pol Alemany * , Marija Gajic § , Ramon Casellas * , Ricardo Mart´ ınez * , Raul Mu˜ noz * * Centre Tecnol` ogic de Telecomunicacions de Catalunya (CTTC/CERCA), Castelldefels, Spain † NEC Laboratories Europe, Germany ‡ Telenor Research, Norway § NTNU, Norway Abstract—This paper presents an inter-domain transport net- work slice management with Service Level Agreements (SLA) us- ing the ETSI TeraFlowSDN (TFS) controller. Different instances of the TFS controller are deployed for each involved domain. The communication between the TFS instances is supported by a Distributed Ledger Technology (DLT)–based database. The different TFS instances upload the abstracted view of their topologies and retrieve that from remote peers. When the end- to-end SLA of the transport network slice is violated, the slice is reconfigured avoiding the domain that originated the violation. Keywords—Network orchestration, DLT, Inter-domain. I. I NTRODUCTION The new generation of services and applications designed to operate on top of 5G and Beyond (B5G) networks are accompanied with an increase in complexity and size of the communication networks. The heterogeneity of technologies involved in the networks and the need to interconnect dif- ferent network domains belonging to different operators pose many new challenges. One of the most prominent challenges concerns the security and privacy of the domain. Network operators want to keep the internal details of their domains private, while offering the high quality Transport Network Slices (TNSs) demanded by their customers with correspond- ing Service Level Agreements (SLAs) [1]. To deploy the inter-domain services in a reliable manner, as imposed by some SLA constraints, the element in charge of establishing the end-to-end connectivity needs to (i) know basic topological information of the domains, and (ii) provide appropriate traceability of inter-domain service requests. To protect the privacy of the network operators and minimize the interactions among them, abstracted network topologies have been proposed in [2]. Then, each domain can upload their per-domain abstracted topological information towards a centralized and permissioned repository accessible to the rest of the domains. The Blockchain technology has been proved to be a feasible solution for uploading and consolidating, in a distributed manner, the information coming from multiple sources and preventing any of these sources from taking ownership of the information [2]. Blockchain prevents data repudiation providing a source of trust for SLA validation. To provide the demanded Quality of Service (QoS) as- surance and traceability of the inter-domain services, some form of leadership between the involved domains needs to be defined. The domain that acts as a leader, should decide the end-to-end path and the list of domains traversed, communicate with the rest of the involved domains, monitor the end-to-end SLAs, and implement the appropriate mitigation mechanisms in case an SLA is violated. Authors in [3] used the Software- Defined Network (SDN) controller instance associated with the source domain of the inter-domain service as the leader. This paper presents the main responsibilities of the Inter- Domain Component (IDC) and the Distributed Ledger Tech- nology (DLT) components we are developing for the ETSI TeraFlowSDN (TFS) controller to create end-to-end transport network slicing services. Among others, these components manage the QoS-aware inter-domain connectivity services and enable the interactions between local and peer TFS instances, each responsible for a different network domain. II. DEMONSTRATION The testbed setup considered for this demonstration is illustrated in Figure 1. The data plane of each domain is implemented as a set of emulated packet routers. On top each domain’s data plane, an instance of the TFS controller is in charge of controlling the respective data planes through NetConf/OpenConfig interfaces. Each instance of the TFS controller features a DLT com- ponent in charge of interfacing with a vendor- and operator– agnostic permissioned Blockchain used to share the per- domain details with neighbor domains. The TFS controller incorporates an IDC component in charge of the interoperation with the remote peers to establish the end-to-end transport network slicing services. All the TFS instances share an abstraction of their respec- tive domain’s topology. The IDC component is also responsible for composing the abstracted view of the local domain that is exposed to the remote peers. In that regard, we follow the approach proposed in [2] where the internal topologies of the